I've now found out that until recently Blackberry phones did not even implement the OBEX protocol (due to security issues).
The 8300 is one of the first phones to actually have it, but it's limited (again for security). There is only one OBEX capable service available (by default) on channel 6: Phonebook Access PSE. Not sure what this service does.
However, when I tell BB to receive a file via bluetooth; a new service is available on channel 7: File Transfer Agent. The file descriptor is OBEX Object Push.
I'm getting discourage that OBEXFTP will not work they way I want it too